Production of caoutchouc from isoprene.



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ARTHUR HEINEMANN, OF SOUTH KENSTNGTON, LONDON, ENGLAND.

PRODUCTION OF CAOUTOHOUC FROM ISOPRIENE.- I

No Drawing.

To all whomit may concern: 1

Be it known that I, ARTHUR HEINEMANN, subject of the King of Prussia, residing at 10 Sumner Terrace, Onslow Square, South Kensington, London, S. W., England, have invented new and useful Improvements Relating to the Production of Caoutchouc from Isoprene, of which the following is a specification.

This invention consists in producing caoutchouc or india-rubber from isoprene by the polymerizing action of ordinary or nascent oxygen or alternatively by the action of ozone.

The essential feature of the invention is that the isoprene is first treated with the oxygen or ozone at a relatively low temperature and is afterward heated as a body to a relatively high temperature, the result being that the isoprene becomes viscous and is eventually converted into a substance having the roperties of natural india-rubber or caoutc ouc.

Referring first tothe polymerization of the isoprene by means of oxygen, the invention may be carried out in the following manner: The isoprene is advantageously cooled while it is being treated with the oxygen. As an example of the relative quantities of oxygen and isoprene and the time of treatment, good results may be. obtainedif 20 liters of oxygen are used for each liter of isopren and the treatment is spread over a peri of six hours. As soon as the isoprene is suiiiciently treated it is placed in a closed vessel to prevent escape of vapor and the vessel heated to a temperaturepf 40-105 C.'for a period of time varying from a'few hours to several days. The heating of the vessel is continued until the iso rene is converted into a viscous mass, a 1' which the vessel is allowed to cool and is then opened. The mass is freed from any unconverted liquid by evaporation or the caoutchouc is precipitated by means of alcohol or other method adopted for obtaining the dry product. The product possesses the properties of natural india-rubber.

The exact mechanism of the action of the oxygen upon the isoprene is a matter of theory, and is not here important, it being suflicient to note the results obtained by the procedure herein described. It may perhaps be that the oxygen, a certain amount of which is absorbed in the beginning of the aeration, produces compounds which are .un-

Specification of Letters ratent.

'tained in different ways.

Patented July 13, 1915..

Application filed June 9, 1911. Serial No. 632,201."

stable and break up into acetic and formic acids and carbon dioxid. The material becomes somewhat acid as a matter of fact.

The isoprene instead of'being used by itself, as above described, may be dissolved in a neutral liquid, for instance benzene. The quantity of india-rubber produced will depend on the temperature and the time during which the heating is continued. At a lower temperature than 100 C. only a-small quantity of india-rubber is produced but at 1001 05 G. a greater quantity is obtained. If the heating is eflected at the higher range of temperature, namely 100-105 G, for a period, of eight days, a yield of approximately fifty per cent. of indie-rubber will be obtained. The heating of the oxidized isoprene is not absolutely necessary as the conversion will be efi'ected without heat if suificient time is allowed. The polymerization of isoprene by means of ozone is effected in the same way as'in the case of oxygen. The ozone acts in the same way as oxygen. v

As above mentioned either ordinary oxygen or the more active nascent oxygenmay be used. The nascent oxygen may be'obmay be produced by the addition to the isoprene of barium peroxid and dilute sulfuric acid, only enough of the latter being used as will be suflicient to liberate the oxygen. Again the nascent oxygen may be obtained from peroxid of hydrogen or by the electrolysis of water.

Having now described my invention what I have invented and desire to secure by Letters Patent of the United States is as fol lows v v 1. A process for the production of caoutchouc from isoprene, comprlsing first passing a substantial amount of a substance composed of oxygen through the isoprene while maintaining the latter at alow temperature, and then heating theproduct fora time sufiicient to effect polymerization.

2. A process for the production of caoutchouc from'isoprene, comprising first passing a substantial amount of free ozone through the isoprene while maintaining the Y latter at' a low temperature, and then heatin the product for a time sufiicient'to efi'ect polymerization.

3. A process for the production of caoutchouc from isoprene, comprislng first passing a substantial amount of a substance For instance it composed of oxygen through the isop'rene While maintaining the letter at at low tem-' persture, she then heating the product to a, temperature oft epprom'metely 105 C. for a time suficient to efiect polymerization.

4:. A process for the proiuction of ceout- ,chouc from isoprene, comprising first pass ing a substantial amount of free ozone through the isoprene While maintaining the letter at a low temperature, and then heating the product to a temperature of epproxt mateiy 105 C. for n time suficient to eflect polymerization.

5, A process for the production o't'ceout 

